Researchers have revealed details of a new species of dinosaur called Oksoko avarsan. It had a parrot-like beak and only two functional fingers on its forearms, one fewer than its close relatives, suggesting an ability to adapt.

The experts behind the study have researched this species for six years.

They say the toothless, feather-covered dinosaur would have lived around 72-66 million years ago, reaching up to two meters in length as an adult.

But, most interesting was the discovery of the evolution of the oviraptor family of dinosaurs: a species that loses a functional finger has never been seen before.

This is evidence of a change in diet and lifestyle.

Sign of evolution

Paleontologist Gregory Funston of Edinburgh University in the UK reports that it is very interesting that the complete skeletons of the Oksoko avarsan species have been preserved together.

This shows that young people wandered in groups.

But, the discovery of only two fingers prompted him to research how the forelimb changed throughout the evolution of oviraptors, which had never been studied before.

This find revealed the key piece of why oviraptors were so diverse before the extinction of all dinosaurs.

The research suggests that the hands and arms of these creatures changed dramatically as they migrated to new parts of the world, such as North America and the Gobi Desert in Mongolia.

Even the bones were discovered in Mongolia.

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Through detailed analysis of other skeletons (identification marks on skulls and forelimbs), the team was able to identify O. avarsan as a new species.

The discovery was confirmed precisely by the tiny protrusion of a bone from the third finger, where a whole finger should have been.

Adaptation for desert life

The gradual loss of fingers would have happened over millions of years.

So researchers think it may have been an adaptation to life in the desert.

In addition to this discovery, the skeletons were recovered in resting poses, so the species probably belonged to social groups.

There is still much to discover about the Upper Cretaceous oviraptors that lived in this part of the world, including the color of their eggs and the nests they built.

But the new study offers some intriguing insights into their evolution and diversification.

The researchers conclude in their paper that oviraptorids appear to have been exceptionally able to diversify and coexist in the late Cretaceous ecosystems of Asia.

Even though they were fewer in number, they were diverse in the ecosystems they inhabited.

So this seems to be the key missing piece to explain this species' ability to adapt to different habitats and food supplies - shown by the switch from three to two functional fingers.

The research was published in the Royal Society Open Science.